the absolute best webcam is the one you might already have!
i have a cheapo tv tuner card (ATI TV VE Wonder) that accepts vidoe inputs.
i have a old camcorder
connect the camcorder to the tv tuner card
set the tuner card input to the camcorder
now you have a "webcam" with autofocus, a great zoom, better optics, and a kickass frame rate.
download appropriate "drivers" from drivers.com to make the tv card output a windows media source,
use messenger 6.2 (seems to avoid problems with firewall ports..i run mine through a linksys router without opening any ports, and it is recieved without problem by my daughter at college through their firewall).
use the cell phone with "free" long distance audio, the internet for the video component...
your best webcam.
by the way, not only can you use a camcorder as the webcam (throuth the tv tuner card), you can also jack a digital camera into the tv tuner card and use it as a video source...i did this with a canon powershot, no problem!